Commit 8837ba3e authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: nf_tables: split async and sync catchall in two functions 



list_for_each_entry_safe() does not work for the async case which runs
under RCU, therefore, split GC logic for catchall in two functions
instead, one for each of the sync and async GC variants.

The catchall sync GC variant never sees a _DEAD bit set on ever, thus,
this handling is removed in such case, moreover, allocate GC sync batch
via GFP_KERNEL.

Fixes: 93995bf4 ("netfilter: nf_tables: remove catchall element in GC sync path")
Reported-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 28628fa9

net/netfilter/nf_tables_api.c

+30 −25
Original line number Diff line number Diff line
@@ -9680,16 +9680,14 @@ void nft_trans_gc_queue_sync_done(struct nft_trans_gc *trans) 
	call_rcu(&trans->rcu, nft_trans_gc_trans_free);

}



static struct nft_trans_gc *nft_trans_gc_catchall(struct nft_trans_gc *gc,

						  unsigned int gc_seq,

						  bool sync)

struct nft_trans_gc *nft_trans_gc_catchall_async(struct nft_trans_gc *gc,

						 unsigned int gc_seq)

{

	struct nft_set_elem_catchall *catchall, *next;

	struct nft_set_elem_catchall *catchall;

	const struct nft_set *set = gc->set;

	struct nft_elem_priv *elem_priv;

	struct nft_set_ext *ext;



	list_for_each_entry_safe(catchall, next, &set->catchall_list, list) {

	list_for_each_entry_rcu(catchall, &set->catchall_list, list) {

		ext = nft_set_elem_ext(set, catchall->elem);



		if (!nft_set_elem_expired(ext))
@@ -9699,35 +9697,42 @@ static struct nft_trans_gc *nft_trans_gc_catchall(struct nft_trans_gc *gc, 


		nft_set_elem_dead(ext);

dead_elem:

		if (sync)

			gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC);

		else

		gc = nft_trans_gc_queue_async(gc, gc_seq, GFP_ATOMIC);



		if (!gc)

			return NULL;



		elem_priv = catchall->elem;

		if (sync) {

			nft_setelem_data_deactivate(gc->net, gc->set, elem_priv);

			nft_setelem_catchall_destroy(catchall);

		}



		nft_trans_gc_elem_add(gc, elem_priv);

		nft_trans_gc_elem_add(gc, catchall->elem);

	}



	return gc;

}



struct nft_trans_gc *nft_trans_gc_catchall_async(struct nft_trans_gc *gc,

						 unsigned int gc_seq)

struct nft_trans_gc *nft_trans_gc_catchall_sync(struct nft_trans_gc *gc)

{

	return nft_trans_gc_catchall(gc, gc_seq, false);

	struct nft_set_elem_catchall *catchall, *next;

	const struct nft_set *set = gc->set;

	struct nft_elem_priv *elem_priv;

	struct nft_set_ext *ext;



	WARN_ON_ONCE(!lockdep_commit_lock_is_held(gc->net));



	list_for_each_entry_safe(catchall, next, &set->catchall_list, list) {

		ext = nft_set_elem_ext(set, catchall->elem);



		if (!nft_set_elem_expired(ext))

			continue;



		gc = nft_trans_gc_queue_sync(gc, GFP_KERNEL);

		if (!gc)

			return NULL;



		elem_priv = catchall->elem;

		nft_setelem_data_deactivate(gc->net, gc->set, elem_priv);

		nft_setelem_catchall_destroy(catchall);

		nft_trans_gc_elem_add(gc, elem_priv);

	}



struct nft_trans_gc *nft_trans_gc_catchall_sync(struct nft_trans_gc *gc)

{

	return nft_trans_gc_catchall(gc, 0, true);

	return gc;

}



static void nf_tables_module_autoload_cleanup(struct net *net)